In Turkey, vitamin D deficiency has been seen in children as well as in their mothers. We assessed the vitamin D status of 83 infants and their mothers, categorized into four groups according to season and mothers' clothing style. We measured serum levels of 25-hydroxy vitamin D, calcium, inorganic phosphorus and alkaline phosphatase in each mother-infant pair. In the summer, the rate of vitamin D deficiency was higher in mothers who wore clothing that covered nearly all of the body (55%) than in mothers whose clothing covered less of the body (13.6%) (p=0.016). In the winter, nearly half of both groups of mothers had vitamin D deficiency or insufficiency, and there were no significant differences based on their clothing style (p>0.05). In all groups of infants, vitamin D deficiency and insufficiency rates were found to be very low. It seems that 400 IU/daily vitamin D intake is adequate for infants in Turkey; for mothers, we propose vitamin D supplementation during the pregnancy and lactation period.